Rear blade mechanism for road grading machines



March 29, 1966 N. s. xvERsoN 3,242,599

REAR BLADE MECHANISM FCR ROAD GRADING MACHINES Lg/MKM ATTORNEYS March 29, 1966 N. s. xvr-:RsoN 3922,59@

REAR BLADE MECHANISM FOR ROAD GRADING MACHINES Filed Feb. 24, 1964 g Sheets-Sheet 2 INVENTOR.

NOBLQL 5 [VERSO/v ATTORNEYS United States Patent O 3,242,599 REAR BLADE MECHANISM FOR ROAD GRADING MACHINES Noel S. Iverson, New Ulm, Minn., assigner to R.K.S., Incorporated, New Ulm, Minn., a corporation of Minnesota Filed Feb. 24, 1964, Ser. No. 346,825 1 Claim. (Cl. 37-155) The present invention relates to mobile road grading machines, and more particularly it relates to an improved rear blade and associated mechanism for road grading machines.

Road grading machines of the type to which the present invention relates normally include an elongated main frame, a front axle, a pair of rear axles, a rear mounted engine, and a generally centrally located scraper or grading blade adjustable about a generally vertical axis. rl`he present invention relates to a supplemental or additional scraper or grading blade mounted adjacent the rear of the machine by a novel mechanism. The rear mounted -blade is particularly useful when arranged according to the present invention for grading to one lateral side or the other of the path of travel of the machine, Such as in the grading of side ditches. An important object of the present invention is the provision of a mobile road grading machine having a rear scraper blade mounted and supported by a novel boom structure.

Another object of the .present invent-ion is the provision of a road grading machine having a rear scraper blade adjustably mounted adjacent the rear of the machine for easy adjustment of the -blade positions with `respect to the machine.

Another object of the present invention is the provision of a mobile road grading machine having a rear mounted scraper blade which is secured in a manner to overcome the tendency of previous mounting means for rear blades to fail when meeting an obstruction.

Another important object of the presen-t invention is the provision of a mobile road grading machine having a rear mounted scraper blade which includes a supporting link element having a shear pin adapted yto break upon engagement of the blade with an obstruction so as to prevent damage to the blade mounting means as previously occasioned.

A further object of the present invention is the provision of a rear scraper blade for a mobile road grading machine which is mounted by means including a horizontal member secured to the machine frame for pivotal movements about a generally vertical axis.

A still further object of the present invention is the provision of a mobile road grading machine having a central scraping blade and a rear scraping blade and in which an adjustable connecting shaft is provided for extension between the rear blade and the central blade so as to provide common adjustable movements of the same.

Other objects and advantages of lthe present invention will become apparent from a consideration of the following detailed specication, attached claims, and appended drawings.

Referring to the drawings, wherein like reference characters indicate like parts or elements throughout the several views:

PIG. 1 is a View in top plan of a road grading machine showing the present invention, and also showing an alternative position of some parts by dotted lines;

Patented Mar. 29, 1966 'ice FIG. 2 is an enlarged View in `top plan of a rear portion of FIG. 1, and also showing alternative positions of some parts by dotted lines;

FIG. 3 is a View in vertical section taken along the line 3 3 of FIG. 2, and showing most patrs in elevation;

rFIG. 4 is a view in section taken on the line 4-4 of FIG. 2; and

FIG. 5 is a view in .section taken on the line 5-5 of FIG. 2.

Referring again to the drawings, and particularly to FIG. 1 thereof, the road grading machine shown there- Iin includes a longitudinally extending elongated main frame comprising a center beam 1, a rear chassis 2 carrying the driven rear wheels 3, and a triangular rear frame section 4. A front axle 5 equipped with wheels 6 is supported by the forward end portion of the main frame, and an engine housing 7 and operators cab 8 are positioned adjacent the rear of the machine, `as shown particularly in FIG. 1.

A generally centrally located scraper blade 9 is carried by an intermediate portion o-f the center beam 1, and `conventional rotary mechanism 10 is provided for adjusting the central blade 9 about a generally vertical axis. Referring to FIGS. 2, 3 and 5, it will be noted that the triangular rear frame section 4 slopes upwardly and rearwardly .and denes a trunnfion having vertically spaced and coaxial end journals 11. The journals 11 specifically comprise the opposite end portions of an elongated rod 12 positioned within a bearing sleeve 13 rigidly secured to the frame section 4, as shown particularly in FIG. 5. The rear scraper blade mounted by the novel mechanism disclosed herein is represented by the reference numeral 14. The mechanism for mounting and supporting the same comprises a boom structure including an elongated horizontal member 15 having opposite end portions 16, 17. In order to mount the end portion 16 of the horizontal member 15 to the rear frame section 4 of the grading machine for swinging movements about a generally vertical axis, the horizontal member 15 is bifurcated to define a yoke having upper and lower yoke Iportions 18, shown particularly in FIGS. 2, 3 and 5. The yoke .portions 18 both define `axially aligned apertulred portions adapted t-o receive the end journals 11 o-f the rod 12. As specifically shown in the drawings, the yoke portions 18 deline end clamps 19 provided for the quick and easy engagement of the same with the journals 11. As shown in the drawings, the rod 12 may be .positioned for rota-ry movement within the bearing ysleeve 13, with the end clamps 19 rigid-ly securing the yoke portions 18 -to the end journals 11 of the rod 12. However, it will be understood -that the rod 12 may be alternatively rigidly secured within the sleeve 13, with the yoke portions 18 forming end bearings for rotation or .pivotal movement with respect to the stationary rod I12. With this in mind, the end portions of the rod 12 are `referred to herein as journals 11, without regard to Whether the rod 12 is disposed for rotation or is stationary with respect to the sleeve 13.

The above-noted boom structure for mounting the rear blade 14 to the grading machine further comprises a vertical member 20 secured at an intermediate portion thereof to the outer end portion 17 of the horizontal member 15, as shown particularly in FIG. 3. A fluid pressure operated cylinder 20a is disposed within the vertical member 2i), and the rear scraper blade 14 is mounted for vertically adjustable movements with respect thereto by means of a ram 21 which has its reduced upper end portion telescopingly received within the cylinder 2tlg. The cylinder a and ram 21 are operated in the conventional manner by fluid pressure provided through the conduit lines 22 for extensive and retracting movements of the ram 21.

The lower end portion of the ram 21 is connected to the rear portion of the scraper blade 14 for limited universal movements. For this purpose, a universal joint 23 is provided, one pivot pin thereof being connected to suitable bracket means 24 rigidly secured to the rear portion of the blade 14. The other pivot pin of the U-joint 23 is connected to a depending fork 25 deiined by the lower end portion of the ram 21. A bridle bar 26 extends around the ram 21 and limits the universal movements of the blade 14, the opposite end portions `of the bridle bar 26 being pivotally secured to spaced brackets 27 secured to the rear side of the blade 14. The intermed-iate portion of the bridle bar 26 extends through a guide element 28 secured to and laterally projecting from the ram 21, the bar 26 engaging a roller defined by the guide element 28. As shown in the drawings guide rollers 29 are also provided in the walls of the vertical member 20 for engagement of the outer surface of the ram 21 through Lcorresponding openings dened in the wall of the vertical member 20.

In accordance with the present invention, a -pair of link elements 30, 31 are connected between the boom structure and the rear portion of the frame 4 of the machine. The link element 30 is of a smaller diameter than the link element 31 and is telescopingly received therein, as shown particularly in FIGS. 3 and 4. The outer end portion of the link element 30 is connected by means of a universal joint 32 to a `portion of the horizontal member 15 adjacent the outer end portion 17 thereof. Also, the outer end portion of the outer link element 31 is connected by means of a universal joint 33 to a portion of the rear frame section 4 in spaced relation to the pivotal connection of the horizontal member 15 thereto. Specically, the U-joint 33 is connected to a bracket 34 projecting laterally from the rear frame section 4. An important yfeature of the present invention resides in the trunnion connection of the horizontal member 15 to the rear frame lsection 4, since with -previous machines of the general type noted herein, such connection was formerly made with a single pivot pin, and upon engagement of the rear blade with obstructions, this single pivotal connection of the previous structures often resulted in a premature failing or shear of the pin. With the present invention, the trunnion connection noted above presents a strong ypivotal connection -able to resist the torsional stress imparted by obstructional displacement of the rear blade ,'14. In this connection, the inner and outer link elements 30, 31 are provided with a plurality of axially spaced alignable apertures 35 so as to permit adjustment of the link elements 30, 31 with respect to one another and thereby adjust the position of the scraper blade 14 and its supporting boom structure. With this arrangement, a shear pin 36 is inserted in the aligned apertures 35 -in the link elements 30, 31 so that if undue stress is imparted to the rear blade 14 by an obstruction, the pin 36 is merely caused to shear and no consequential damage is imparted to the machine or mechanism. FIGS. 1 and 2 of the drawings illustrate various positions of the rear scraper blade 14 and its associated boom structure which may be attained by adjusting the link elements 30, 31. Also, the link elements 30, 31 may be secured by suitable brackets and pivot pins to the opposite lateral side of the machine so as to further adjust the position of the scraper blade 14, as particularly illustrated in FIG. l of the drawings. The bracket for connecting the universal joint to the side of the boom opposite that shown in FIG. 2 lhas been omitted for the sake of clarity.

In order to provide adjustment for the slope or angle of the rear scraper blade 14 about its pivotal connection provided by the U-joint 23 to the ram 21, a fluid pressure operated cylinder 37 and cooperating piston 38 are provided. As shown particularly in FIG. l, the cylinder 37 is connected by a suitable bracket 39 to the upper end portion 40 of the vertical member 20, and the piston rod 38 is pivotally connected by means of a bracket 41 to a portion of the blade 14 in outwardly spaced relation to the pivotal connection thereof to the ram 21. Fluid under pressure is supplied to the cylinder 37 in a conventional manner by means of a iiexible conduit 42, so as to provide extensible and retractable movements of the piston 38 with respect to the cylinder 37 and thereby provide tilting or sloping movements for the scraper blade 14.

In accordance with present practices, adjustable connecting shafts 43, 44 extend between the rear blade 14 and the central blade 9 so as to provide common adjustable movements between the same; The outer shaft 43 is of a larger diameter than the inner shaft 44 which is telescopingly received therein, and secured thereto by means of a pin 45. As shown particularly in FIG. 1, the rear shaft 43 is pivotally secured to the rear scraper blade 14 by means of a bracket 46, and the forward shaft 44 is also pivotally secured or connected to the outer end 4portion of the central blade 9 by means of a bracket 47.

This invention has been thoroughly tested and found to be completely satisfactory for the accomplishment of the above-noted objects; and while a preferred embodiment thereof in which the principles of the present invention have been incorporated has been shown and described above, it `should be specifically understood that the same way be modied without departure from the scope and spirit of the appended claim.

What is claimed is:

In a mobile road grading machine:

(a) a longitudinally extending main frame,

(b) an adjustable central scraper blade supported by said main frame,

(c) a rear scraper blade,

(d) a boom structure for adjustably mounting said rear blade to said main frame, said boom structure comprising:

(l) an elongated horizontal member having opposite end portions,

(2) means mounting one end portion of said horizontal Vmember to the rear of said main frame for swinging movements about a generally vertical axis,

(3) a generally vertical post member secured to the other end of said horizontal member,

(4) means mounting one portion of said rear blade to a lower end portion of said vertical post member for vertically adjustable movements with respect thereto,

(e) adjustable link means pivotally connected at one end portion thereof to said boom structure and at another end portion thereof to said frame in spaced relation to the pivotal connection of said horizontal member to said frame, and

(f) an adjustable connecting shaft extending between said rear blade and said central blade for common adjustable movements,

(g) the rear of said main frame including a trunnion having vertically spaced and coaxial journals and in which said one end -portion of said horizontal member is bifurcated to dene a yoke having spaced bearings engaging said journals,

(h) said adjustable link means comprising a pair of link elements telescopingly connected with one another, a shear pin securing said link elements to one another, and a pair of universal joints one of which forms the pivotal connection of one of said link elements to said boom structure and the other of which forms the pivotal connection of the other 5 6 link element to said frame, and means for Secur- 1,153,508 9/ 1915 Magruder 37-155 ing said joints to opposite sides of the frame and 2,491,797 12/ 1949 Burns etal 37-105 boom whereby the boom can be secured in pre- 2,640,286 6/ 1953 Briscoe 37-155 selected positions on opposite lateral sides of the 2,659,988 11/ 1953 Braden etal 37-155 frame. 5 2,847,772 8/ 1958 McMullen 37-155 3,049,822 8/1962 McMullen 37-155 References Cited by the Examiner UNITED STATES PATENTS ABRAHAM G. STONE, Primary Examiner.

348,941 9/ 1886 Witt 172-271 X W. A. SMITH, III, Assistant Examiner. 

